The correct process for a built up torch on felt system should comprise of 3 layers one base layer manually fixed to the roof usually nailed followed by one torch on underlay with the top finished with a torch on mineral cap layer.
How to use torch on roofing felt.
The top membrane sheet to a torch down roofing system is a smooth cap sheet.
There are two different types of torch down roofing systems.
A three layer torch down roof features the same base and cap sheets as well as an additional cap sheet with a granulated surface.
Move the nozzle across the flashing to coat them in an even opaque layer of primer.
When the two layers are pressed together they form a seal.
You will also find liquid primers.
Make sure you choose something compatible with torch down roofing.
A two layer torch down roof consists of one base sheet and one smooth cap sheet.
Drag it gently from one end of the roof to the other east to west or west to east.
In a two layer torch down roof the system is complete at this point.
These thick layers of roofing felt are installed by heating the back of the felt with a butane torch and then carefully applying it to the roof.
Apply waterproof paint or primer to promote felt attachment.
Use a 4 inch 10 cm paintbrush or a roller to apply the paint or primer.
Torch on roofing or torch down roofing as it is also known is a flat roof covering solution that involves three layers of modified bitumen felt melt welded onto the roof surface and each other with the use of a blowtorch to create an impenetrable waterproof seal.
Two layer and three layer torch down roof systems.
Installing the roofing felt does take care but can go very quickly.
At the gutter edge should be what s known as a welted drip edge.
As it is rolled out the roofing professional will use a torch to heat the bottom of the cap to the top of the base sheet.
Begin at the bottom working in horizontal lines and gradually moving upward.
Two layer torch down roofing may cost less.